have a 69 skylark thinking about 20s on back 18s on front wondering if anybody has done this yet if so what backspace and width of wheel need to know if i can fit 20x9.5 also should i get the same backspace on the front?
Love your tag line ..... I am probably going with the newstalgia wheels Buick 17" billet rims. Backspacing is the issue with our cars ..... keep posting to help us out.
The wheel diameter should have nothing to do with backspacing requirements. What works on a 15" wheel will work on a 20" wheel. I'm not really up on the 68-69's, but on my 70, in front, 4 1/4" to 4 1/2" backspacing works best depending on wheel width and tire size. Out back, 4 1/2" to 5 1/2" backspacing will accommodate just about any tire size again depending on wheel width and tire size.
The best thing I tried is call billet specailties, budnik, b. cottington, etc. tell them your application and they should be able to make your rims to fit if you have the stock length rear axle. Also the rim companies I listed are a bit more pricey but alot better quality and adds value to your ride. I know a few people who put the cast aluminum 18-20-22's on their rides and the rims crack easy when hitting pot holes with those rubber band tires. I've got 18's on my skylark and they're eagle brand. There also a good wheel and they are pretty reasonable on prices.:3gears:
how about biggest rear tire setup on a '69? I've got a '69 and I'm only using 15" wheels. Someone once told me the biggest rear tire I could fit in there was a 295/60, but to be safe, a 275/60. I wanted something bigger, but I don't want to go to any extremes... I'm thinking I'll need mini-tubs to get a 315-325 back there but will I have to change anything but the inner wheelhouse to do this? I've obviously never done this before, only squeezed in the biggest one I thought could fit LOL...
275 60s or a 295 50 should fit in yur 68 with the correct back spacing..not sure on what you need but i bet it'll be about 5 1/4 bs
An article in an issue of Car Craft magazine states that on the GM A-body platform it is possible to stuff a 18 x 11 rim with 5.5-inch backspacing in the rear using a 315 tire and 18 x 9.5 in front with a 275 tire. They claim that this can be done with no body or frame mods but I can't vouch for that.
I have to chime in on a comment Skylark66 said, "The best thing I tried is call billet specailties, budnik, b. cottington, etc. tell them your application and they should be able to make your rims to fit if you have the stock length rear axle. Also the rim companies I listed are a bit more pricey but alot better quality and adds value to your ride. I know a few people who put the cast aluminum 18-20-22's on their rides and the rims crack easy when hitting pot holes with those rubber band tires. I've got 18's on my skylark and they're eagle brand. There also a good wheel and they are pretty reasonable on prices" This week only, I have repaired one budnik wheel, and two(same car) boyds. All three cracked in the same spot as all the dozens and dozens of wheels I've repaired. Forged, casted, big name, no name they all crack the same, and it doesn't always have to be on a rubber band tire i.e. 25 series to crack. The boyds were mounted to 265-50-20 tires. The big name wheels are WAAAAY over rated and WAAAAY over priced, and not that better quality. :beer
I have 245/45/17's Boyd Coddington Smoothie II's on the rear of my 69, and 225/45/17's. Backspacing is "standard", I think that is 4 inch? If they had more backspacing, you could get more tire on the back, but without it, I had to trim a tiny bit out of the wheelwell. I think there was a thread here were someone else researched it and figured out how much backspacing you could fit. If you search on "69 backspacing" you might find it. 68/69 wheelwells are different than 70-72, so what fits on those cars will not necessarily fit on the 68/69's. A really good tire shop should be able to take measurements for you, they make a tool that allows you to accurately measure whether a rim will fit or not.
